BP's 'top kill' operation has failed to plug the oil leak in the Gulf. The company is now planning to cut off the damaged riser from which the oil is leaking and cap it with a containment valve. (May 29)

BP's three-day effort to throttle the leaking gulf oil well with multiple blasts of heavy mud has failed. The attempted "top kill" of the well was abandoned late Saturday afternoon, leaving the huge Macondo field deep beneath the sea floor once again free to pump at least half a million gallons of crude a day into the gulf.

"I can say we tried. But what I can also say is this scares everybody, the fact that we can't make this well stop flowing, or haven't succeeded in that so far," Doug Suttles, BP's chief operating officer, said in a late-day news conference.

The top kill -- a term most Americans had never heard until it became part of the new national vocabulary along with "blowout preventer," "containment dome" and "junk shot" -- had been seen as the best hope for turning the oil spill into something finite in volume. Now BP must fall back on a containment strategy in the near term, hoping to capture as much oil as possible.

Sitting on the sea floor and awaiting deployment is a new containment dome, what the company calls the Lower Marine Riser Package cap. With robotic submarines, the company will sever the leaking, kinked riser pipe that emerges from the top of the blowout preventer, the five-story-tall contraption on top of the wellhead. Then engineers will guide the LMRP cap onto the pipe. The cap is fitted with a grommet designed to keep out seawater and prevent the formation of slushy methane hydrates that bedeviled an earlier containment dome effort. The cap procedure will take four to seven days, officials say.

"This operation should be able to capture most of the oil," Suttles said. "I want to stress the word 'most,' because it's not a tight, mechanical seal."

After that, the company could place another blowout preventer on top of the existing one. Meanwhile two drilling rigs at the surface continue to drill relief wells. That's a long-term strategy that requires engineers to hit a seven-inch target, the bottom of the leaking well, 3 1/2 miles below the surface of the gulf. The first of the two relief wells to hit the target will send a massive dose of cement to seal the leaking well.

That will not be until August, BP predicts.

Saturday's news was hardly a shock, given the doubts expressed by engineers and even by BP itself about whether it's possible to kill a well 5,000 feet below the surface and accessible only with robotic vehicles. But the gulf was still hoping for good news. After BP executives began the top kill Wednesday, chief executive Tony Hayward said the effort was proceeding as planned. Then the national incident commander, Thad Allen, gave news media interviews Thursday and Friday suggesting that the effort was going well. As he put it, "We'll get this under control."

The well had other ideas. It ceased to spew oil only when it was force-fed the drilling mud. When the pumping stopped, the well returned to form, churning out oil and gas. It was like hitting a Bozo punching dummy -- it goes down, then springs back up. Though some might prefer the analogy of the slasher-movie villain who always comes back for the sequel.